Buggy code:
public class NewMessagingSubsystemParser implements XMLStreamConstants , XMLElementReader < List < ModelNode > > , XMLElementWriter < ModelNode > { private static final NewMessagingSubsystemParser INSTANCE = new NewMessagingSubsystemParser ( ) ; public static NewMessagingSubsystemParser getInstance ( ) { } private NewMessagingSubsystemParser ( ) { } public void writeContent ( final XMLExtendedStreamWriter writer , final ModelNode node ) throws XMLStreamException { } public void readElement ( final XMLExtendedStreamReader reader , final List < ModelNode > list ) throws XMLStreamException { } static ModelNode processAcceptors ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static ModelNode parseQueues ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static void parseQueue ( final XMLExtendedStreamReader reader , final ModelNode queue ) throws XMLStreamException { } static ModelNode processSecuritySettings ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static void parseSecurityRoles ( final XMLExtendedStreamReader reader , final ModelNode node ) throws XMLStreamException { } static ModelNode processConnectors ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static ModelNode processAddressSettings ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static ModelNode parseAddressSettings ( final XMLExtendedStreamReader reader ) throws XMLStreamException { } static void parseTransportConfigurationParams ( final XMLExtendedStreamReader reader , final ModelNode transportConfig , final boolean generic ) throws XMLStreamException { final ModelNode params = new ModelNode ( ) ; while ( ( reader . hasNext ( ) ) && ( ( reader . nextTag ( ) ) != ( XMLStreamConstants . END_ELEMENT ) ) ) { int count = reader . getAttributeCount ( ) ; String key = null ; String value = null ; for ( int n = 0 ; n < count ; n ++ ) { String attrName = reader . getAttributeLocalName ( n ) ; Attribute attribute = Attribute . forName ( attrName ) ; switch ( attribute ) { case KEY : key = reader . getAttributeValue ( n ) ; break ; case VALUE : value = reader . getAttributeValue ( n ) ; break ; default : throw unexpectedAttribute ( reader , n ) ; } } Element element = Element . forName ( reader . getLocalName ( ) ) ; switch ( element ) { case FACTORY_CLASS : { if ( ! generic ) { throw ParseUtils . unexpectedElement ( reader ) ; } transportConfig . get ( FACTORY_CLASS ) . set ( reader . getElementText ( ) . trim ( ) ) ; break ; } case PARAM : { <START_BUG> params . set ( key , value ) ; <END_BUG> ParseUtils . requireNoContent ( reader ) ; break ; } default : { throw ParseUtils . unexpectedElement ( reader ) ; } } } transportConfig . get ( PARAM ) . set ( params ) ; } static ModelNode parseDirectory ( XMLExtendedStreamReader reader ) throws XMLStreamException { } static void unhandledElement ( XMLExtendedStreamReader reader , Element element ) throws XMLStreamException { } static void handleElementText ( final XMLExtendedStreamReader reader , final Element element , final ModelNode node ) throws XMLStreamException { } static void writeSimpleElement ( final XMLExtendedStreamWriter writer , final Element element , final ModelNode node ) throws XMLStreamException { } static void writeDirectory ( final XMLExtendedStreamWriter writer , final Element element , final ModelNode node ) throws XMLStreamException { } }

Fix:
params . add ( key , value ) ;